> the main tone is at 440 Hz The largest tuning fork in the world! [1] [1]: https://en.wikipedia.org/wiki/A440_(pitch_standard) https://en.wikipedia.org/wiki/

> the main tone is at 440 Hz The largest tuning fork in the world! [1] [1]: https://en.wikipedia.org/wiki/A440_(pitch_standard) https://en.wikipedia.org/wiki/A440_(pitch_standard)